Filter.



No. 866,401. I PATENTED SEPT. 17, 1907.

J. B. STEWART. v

FILTER.

APPLICATION rmm 11.30, 1001.

WITNESSES a: INVENTOH A TTOHNE YS THE NGRRIS PETERS co., wqsumomn, n. c.

PATENTBD SEPT. 17, 1907.

J. B. STEWART.

FILTER.

APPLICATION rum) JAN. 30. 1907.

2 SHEETS-SHEET 2.

WITNESSES: I

INVENTOI? I 70k n/fiv iewal'ef I M ATTORNEYS THE NORRIS PETERS ca, wAsl-I'mu'rqu, n. c.

JOHN BURGOYNE STEWART, OF PEREGRINA, MEXICO.

FILTER.

Specification of Letters Patent.

Patented Sept. 17, 1907.

Application filed January 30, 1907. Serial No. 354,793.

To alZ whom it may concern:

Be it known that I, .loHN BURGOYNE STEWART, a citizen of the United States, and a resident of the town of Peregrina, in the State of Guanajuato, Mexico, have invented a new and Improved Filter, of which the follow ing is a full, clear, and exact description.

This invention is an improved filter designed to be used for the purpose of the filtration of gold and other precious metal solutions from slime or pulp.

In the separation of gold from its ore it is first crushed by machines known as stamps and passed over amalgam plates which remove the larger particles of metal from the sand or quartz. After this operation a quantity of gold still remains in a finely divided state, which is usually removed by the cyanid process. This consists in treating the finely divided material with potassium cyanid; which solution dissolves the metallic gold, forming a double cyanid of gold and potassium. A considerable quantity of this double cyanid of gold andpotassium can be removed from the powdered rock and sand with which it is intermixed and known as slime, by settling, but a portion of such solution remains with the slime which heretofore it has been unprofitable to separate and has been thrown away.

The object of this invention is to provide means whereby when the cyanid solution has been removed so far as possible by settling, the remainder may be squeezed or filtered out and the pulp delivered in a continuous stream so low in moisture as to be capable of stacking in dumps, to which it may be delivered by any suitable mechanical means.

The filter is so constructed that it can operate at a high pressure with a fairly rapid rate of discharge, which may be accelerated or retarded according to the nature of the slime to be passed through it, some of which will necessitate washing, an addition of cyanid solution, air or steam pressure, all of which the filter is constructed to supply.

Reference is to be had to the accompanying drawings forming a part of this specification,' in which similar characters of reference indicate corresponding parts in all the figures.

Figure l is a plan view of the filter suspended over a vat; Fig. 2 is a longitudinal, horizontal section of the filter, and Fig. 3 is a transverse, vertical section of the same on the line 33 of Fig. 2.

The filter'is made up of an outer metal casing com- I prising a cylindrical drum 1 flanged at each end, to which are attached conical metal ends 2 also flanged and connected with entrance and exit pipes 3 and 4, respectively. The joints between the several sections of the filter are preferably constructed with an intervening gasket, insuring an air and liquid tight joint between them.

Supported concentrically of the outer casing is an in ner casing of the same shape, but preferably constructed of lighter material, comprising a drum 5 joined to conical ends 6 adjacent to, and inclosed by the conical ends 2 of the outer casing. The inner casing is provided with bulkheads or partition walls 7 separating the conical ends from the cylindrical portion of the easing, and partition walls 8 at the center of the cylindrical portion, dividing this part of the filter into four different chambers or compartments respectively indicated by the numerals 9, 10, 11 and 12. Secured to the walls 7 are twisted metallic strips 7 radiating from the center of the filter, passing through the inner casing and sup porting it concentrically with the outer casing.

Covering each section of the exterior casing of the filter is some filtering material as canvas, jute or asbestos 13, which is held in place by wire gauze or netting 14 passing about it, all of which is secured against dis placement from the casing by hoops 15 passing around the cylindrical portion as well as the conical ends.

, The outer casing is provided with a series of periorations 16 passing around it in both the conical ends and drum portion, for allowing the escape of the solutionthrough them and through the filtering material from the slime as the latter is forced through the filter.

The interior drum is also provided with perforations l6 in all of its compartments, or in so many of them as it is desired, which will vary according to the slime to be operated upon. The filter thus constructed may be suspended in a vat 1'7 for collecting the solution, and has leading to the several compartments of the inner casing a pipe system comprising a main pipe line' 18 having a valve 19 at its center, and pipes 20, 21, 22 and 23 leading from it, two at each side of the valve, respectively, to the compartments 9, 10, 11 and 12. Each of these pipes is in turn also provided with valves 24 and pressure gages 25, indicating at all times the pressure maintained in any compartment. The outer pipes 20 and 23 are connected with feed pipes 26 and 27, and have valves 28 at some suitable point of their length to cut off communication between them and the respective pipes with which they connect, when necessary.

A pipe 29 havinga valve 30 passes into the compartment 12 and into the discharge end of the filter in the direction of the outgoing pulp, and is intended to be used, when necessary, to admit steam, compressed air or some other suitable medium for assisting a more rapid discharge of the pulp. A valve 31, or suitable adjustable exit, in the discharge pipe 4 can be operated when desired to increase or diminish the flow.

In the operation of the filter, the slime containing the gold in the cyanid solution is delivered through the pipe 3 by a force pump or other suitable device, which causes it totravel through the annular space between the inner and outer casings of the filter, squeezing out the solution through the perforations 16. Air or steam pressure will, in some instances, be introduced into one or all of the compartments of the inner casing to assist in the squeezing process as the filtering progresses, and solutions or Water used for washing in final stages of treatment.

If the slime should be of such a nature that during the filtering operation it should be moistened in any part of the filter, or treated with cyanid solutions of different strengths, the pipe system is so arranged that a different medium may be conveyed to each compartment. By means of this construction, the slime about one compartment may be subjected to air or steam pressure; another may be treated with cyanid solution of one strength", another may be treated with cyanid solution of a different strength or Water, while the fourth may be treated with nothing, or water etc. The exact treatment of the slime in the several compartments is, of course, to be determined by the condition of the ma terial operated on and the state in which it is desired to discharge it from the filter.

Although I have described the details of construction of the invention, it is to be understood that the scope thereof is limited by the annexed claims only.

Having thus described my invention 1 claim as new and desire to secure by Letters Patent:

1. In a filter for ore slimes and the like, an outer casing, an inner casing, a filtering material carried by the outer casing, means for dividing the inner easing into several compartments, and a pipe system for supplying said compartments with the same or a dilferent medium, as desired.

In a filter for ore slimes and the like, an outer casing, an inner casing concentrically supported in the outer cas lug leaving an annular space between them, a filtering material carried by the outer casing, an entrance pipe and an exit pipe leading to and from the casing whereby a con tinuous flow of the material is maintained, and means for treating the slime with different mediums as it is advanced through the filter.

3. In a filter for ore slimes and the like, a casing, means for passing a continuous ilow of slime through the casing, and means for treating the slilne with different mediums as it passes through the casing.

4. In a filter for ore slimes and the like, an outer casing, a filtering material carried on the exterior thereof, an inner casing arranged concentrically to the outer casing, said inner casing being divided into a plurality of compartments, and means for admitting different mediums to said compartments.

5. In a filter for ore slimes and the like, an outer perl'orated casing, a filtering material carried thereby, an inner casing concentrically supported in the outer casing, forming an annular space between them, a receiving and discharging pipe respectively connected at opposite ends of the casing, and means for treating the slime to different mediums as it passes through said annular space.

6. In a filter for ore slimes and the like, an outer perforated casing, a filtering; material carried thereby, an inner casing, said inner casing being divided up into several compartments, the inner casing having perforations passing therethrough, means for admitting different or the same medium into said compartments, and means passing into the compartment adjacent to the discharge end of the filter for assisting in more rapid discharge of the slime.

7. In a filter for ore slimes and the like, an outer perforated casing, an inner casing supported therein, said inner casing being divided up into several compartments, a. pipe system connecting with each compartment whereby they may be supplied with the same or a different medium, and a pressure gage provided for each pipe.

8. In a filter for ore slimes and the like, an outer perforated casing, 11 filtering material fixed thereon, a wire mesh fabric embracing the filtering material, hoops clamping said fabric and filtering material to the casing, an inner casing supported in the outer casing forming an annplar space between them, said casings having a receiving and discharge opening respectively at opposite ends of said space.

9. In a filter for ore slimes and the like, an outer casing comprising a central, cylindrical drum having conical ends attached thereto respectively connecting receiving and exit openings, said casing being perforated and having a filtering material secured thereto, an inner casing supported in the outer casing of substantially the same shape and di vided into several compartments, and means for supplying said compartments with different or the same mediums whereby the slime is treated as the filtration progresses.

10. In a filter for ore slimes and the like, a vat, an outer perforated casing supported over the vat, said casing hav ing receiving and exit openings respectively at opposite ends thereof, a filtering material carried by the outer casing, a perforated inner casing supported in the outer casing, compartments in the inner casing, and means for supplying the same or diiferent mediums to the compartments, as described.

11. In a filter for ore slimes and the like, an outer-perforated casing, a filtering material fixed over the perforations on the exterior of the casing, an inner casing supported in the outer casing and forming an annular space between them, the casings having a receiving and a discharge opening at respectively opposite ends of the annular space, perforations in the inner casing, means for dividing the inner easing into several compartments, a pipe system for supplying the compartment with the same or a different medium, as described, means for indicating the pressure in each compartment, and means passing into one of the coinpartments for facilitating the discharge of the slime afterit has passed through the filter.

12. In a filter for ore slimes and the like, an outer perforated casing, a filtering material fixed over the perforations or the casing, a wire meshed fabric surrounding the filtering material, hoops clamping the fabric and filter ing material to the casing, an inner perforated casing, means for supporting the inner casing concentrically with the outer casing, forming an annular space between them, said casings having a receiving and discharge opening respectively at opposite ends of the annular space, bulkheads dividing the inner easing into several compartments, a pipe system having a pipe leading to each compartment whereby they are supplied with the same or a different medium, means for assisting the discharge of the slime after it has passed through the filter, and a valve at the discharge end of the filter for regulating the flow.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN BURGOYNE STEWART.

Witnesses l\L\URICE STRAUSS,

I. L. LTYAN. 

